<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>JS的三种引入方式</title>
</head>
<body>
    <button onclick="alert('请先登录')">点击即玩</button>
    <button onclick="console.log('去你妈的')">点击即玩2</button>

    <h1 id="h1">一级标题</h1>
    <script>
        console.log(h1);
    </script>

    <!--引用外部的Js文件-->
    <script src="01.js">
        console.log("看你妈个头")
    </script>
</body>
</html>